Bore mining apparatus with strata sensing means



April 1o,'.1956

F1155 pecl 1, 1251 l' sHALa COAL CLAY' nwswrcznA l PAUL L. ALS .QUG BY WET CLAY sANosToNs Time @la u. 15 v KATTORNEX laul L. Alspeufh. South f" apparatus for a bore r chine is leaving the coal seam.

" F'.z,v4i,.st sff Borne Mimi-vc .tensiones vtrrn smarts sensors-MEANS "L il'. Va., assigner to Union Ca: de and Cai o!" New York strata being cut by a boring machine.

s ation, :x corporation In many bore mining operations, such as when using' Va horizontal boring machine for'the mining of coal, it is extremely important'to keep the machine working in a scarnof coal and out of adjacent strata of roch or clay.

to a control pomt remote from the cutter bits of the boring machine so that the machine can be shut off, either manually or auto damaged in the a...

It is an object o to Acut through rock.

machine which will con:`

tinuously respond to the nature of strata being cut by the machine.

ltl is a further object to provide an apparatus for a bore mining machine which 'rapidly responds to changes in nature of strata and rapidly conveys this intelligence to the remote point.-

Other objects' and advantages of this invention will be apparent during the course of the following description.

lt has been found that the temperatureef the cutterv bits of a boring machine greatly and rapidly increases as 4the hardness of the strata encountered increases. -The present invention, based on this phenomenon, employs a therrnocouple mounted'in one of the forwardly located outer teeth of the boring machine. As th: machine begins to leave the coal seam there is a rapid temperature change in the tooth. lf the tooth enters an area of roel; after leaving thc seam there will be a rapid increase in its temperature, while a drop in temperature will occur if4 clay or a similar soft strata is encountered. The thermo couple mounted in the temperatme sensitive scanner tooth tically, before the cutting teeth are sent invention to provide an assembly embodyi .c tit.: rescntinvenfion; and

'mounted o: a rotary cutting head 3 of a horizontal iwf 'ing machine for mining suo-strata material 4. A suitable A therrnocouple 5,' such as an iron-constantan thermocouple.

is mounted in bore o of scanner tooth 1. Electrical connections 7 are provided between the thermocouple and a conventional therrnocouple meter 8 calibrated in degrees Fahrenheit and mounted in the contmlhouse of the boring machine. Suitably. automatic cutoff relay means 8a may be provided to stop thev bore mining machine when roei; is encountered. as indicated by ther'rnooouple response. Slip rings 9 provide a closed electrical circuit verneem the thcrmocouple and the meter capite the rotation of cutter head 3.

As is shown in greater detail in Fig. 2. the scanner tooth 1 has a tapered shank 10 tted into a met-2l sleeve 11 which. in turn. is mounted in hollow bracket 12. ,A set screw 13 threaded in-a lateral hole in the bracket 32 engages and helps to hold metal sleeve 11 in position.

The bracltet l2 is Vwelded to assembly-supporting inem- ,ber 14 which, in turn. is secured to the cutter headk 3 by bolts 15. Electrical connections 7 from thermocotrple 5 are carried through arm assembly 2 to slip rings 9 by means of cable 16.

An apparatus embodying the present invention has been employ'edin' combination with a horizontal rotary coal boring machine; as described in the copending application Serial No. 85.222, led April 2, 1949, and entitled "s/tin ing Machine. now Patent Number 2,699,328. A rotary cutting head of such a machine is chown, in end view, in Fig. 3 of the drawing. While cutting along a coal seam under normal conditions. at a rate of advance ol l2 inches a minute and a cutter head speed of 60 revolutions per minute, the temperature of the scanner tooth as indicated by the thermocouple meter, was approxi is electrically connected to a remote control point and thereby conveys temperature readings to a meter at that point. 'By observing the meter temperature'readings the operator can stop and change the direction of' the boring machine whenever these readings indicate that the mai I M an alternative to thermocouple temperature readings a... manual operation, the thermocouple voltage canbe used toactuate a conventional relay which breaks the power circuit thereby stopping the cutter head motion whenever the machine leaves the coal seam.

ln the accompanying drawings:

Fig. l is a schematic view showing thescanner cutting tooth of the 'present invention and the electrical connections between the tiermocouple mounted in the scanner tooth and the indicating meter at a point remote therefrom;

Pig. 2 is a view, parl): in elevation and partly in cross section, ot' a scanner tooth assembly embodying the present invention;

Fig. 3 is a view, partly in iront elevation and partly.

mately F. v At times when the machine encountered a clay crack, verified later by observation of the materia." delivered to the conveycr system of the machine, and by visual inspection of the hole after completion of the cutting operation, the observed thermocoupie temperature dropped sharply to 100" F. within 3-5 seconds. lr one case. an extremely wet .clay stratum caused the temperature to drop to 75 F. A narrow band o f sandstone was encountered causing the thermocoupie temperatur: to rise to 175 F. Temperatures exceeding '225'a F. have been observed when ide bands of roel; were enconn tered. The indicated meter readings ot temp-e:y re plotted asa function of time, for the cutting operario: described above, are shown in Fig. 4 of tbe drawing.

During these bore mining operations the apparatus em bodying'the present invention has shovm a very rapid response to variations in strata nature. When the sandstone band was encountered, the response time for the 25-degree increase in indicated temperature was betweer one and two seconds.

The wide range of thermocouple temperature variatie! together with good response 4time provides rapid ani accurate means for determining the nature nf strat: encountered by the cutting tooth of a bore mining machine. and, whether used to indicate scanning tooth tem pereture for manual operation cr for automatic cutoff serves the purpose o preventing damageto the cutting tooth then roei; is encountered.

hat is claimedis: i

ln a entre mining machine having a rotary cuttcrheax adapted '.o be advanced into desired strata o material te 

